With or without masks, Aspenites breathe fairly clean air during pandemic

Aspen might have a mandatory mask law in place, but the city’s air quality is nothing to sneeze at these days.

The U.S. Air Quality Index over the week, including Saturday, has put Aspen in the 36-38 range, which basically means the air you’re breathing is fairly clean with scarce pollutants. Anywhere between 0 and 50 means “good” air quality, the best ranking available on the 1-500 scale.

“It’s slightly better than we would expect to see now,” said C.J. Oliver, director of the city’s Environmental Health and Safety Department. “Our air quality is really good with less traffic on the road, fewer restaurants open and grilling, and I also think less use of one of our sources of PM10 in town — all of the fireplaces in all of the residences with so few second-home owners in town.”

PM10 is a major polluting particle found in dust and smoke, and is factored into the air quality index along with PM2.5, a finer particulate matter that can be generated by automobiles, for example. Ground level ozone — which can cause smog — also is part of the air quality index.

The city does not test for carbon emissions, Oliver said.

A suspension construction activity since April 1 due to a public health order also has had an impact on the air quality, Oliver said, with less traffic coming into town and less dirt flying. The industry resumed work Monday after the order was lifted.

“It’s an obvious impact on the air quality, from the digging to the snowpiles being exposed to the jackhammers,” he said.

A study from Harvard last month also showed that people who live in places with long-term air pollution have a better chance of dying from the COVID-19 virus.

Levels of PM2.5 exceeding 13 micrograms per cubic meter of air are considered a high pollution level, the study noted. On Saturday morning Aspen’s hourly PM2.5 level was 2 micrograms per cubic meter of air, while its 24-hour rolling average was 4.

“A small increase in long-term exposure to PM2.5 leads to a large increase in the COVID-19 death rate,” the study said, adding while the results are limited, they “underscore the importance of continuing to enforce existing air pollution regulations to protect human health both during and after the COVID-19 crisis.”